Flora of North America species comparison

long-creeping, branched, branches 2–3-forked, flat, not articulate, glabrous.

radially symmetric, underground (rhizomatous) and aerial, not readily fragmenting, irregularly forked; rhizomatous and aerial stems often with 1 branch arrested, budlike, tips straight;

aerial stems erect, less often ascending, cespitose, stout, branches not conspicuously arrested, budlike branches mostly near base.

delicate and papery.

dimorphic, not clearly ranked.

paired, 0.6–1.1 cm;

sporophylls monomorphic, ovate-lanceolate, keeled, keel not dentate, base glabrous, margins green, entire or with a few scattered, short cilia, apex acute to acuminate.

solitary, (0.7–)1–3 cm;

sporophylls narrowly ovate-lanceolate to lanceolate, abaxial ridges prominent, base glabrous, margins denticulate to short-ciliate, apex keeled, bristled.

borne on underside of stems throughout stem length or restricted to proximal ± 2/3 of main stem or axillary throughout stem, 0.2–0.4 mm diam.

borne on upperside of stems, mostly restricted to rhizomatous stems or to lower 1/2 of aerial stems, 0.16–0.26(–3) mm diam.

leaves spreading or slightly ascending, distant, shiny green becoming shiny brown, with orange or red spot or entirely reddish, ovate to ovate-oblong or oblong, 1.5–3.2 X (1–)1.5–2.2 mm;

base auriculate, basiscopic auricle conspicuous, acroscopic auricle inconspicuous or base ± rounded;

margins green, ciliate toward auricles, otherwise entire;

apex rounded to obtuse or truncate.

leaves ovate-oblong, (1.8–)2–2.2 × 1–1.3 mm;

base auriculate, outer auricle larger than inner one;

margins green, ciliate at auricles, otherwise entire;

apex abruptly cuspidate to bristled.

stem leaves persistent, loosely appressed, ascending, often incurved, scalelike.

stem leaves tightly appressed, ascending, green, linear-lanceolate to narrowly lanceolate, 1.7–2.4 × 0.36–0.43 mm;

abaxial ridges prominent;

base cuneate and decurrent on main stem or rounded and abruptly adnate on apical branch portions, glabrous or pubescent;

margins short-ciliate at base, cilia transparent, spreading, denticulate, and ascending toward apex, 0.03–0.06 mm;

apex keeled;

bristle transparent to opaque or yellowish to brownish (on old leaves), puberulent to smooth, 0.3–0.6(–0.7) mm.

= 18.